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reranker-cohere

Introduction​

  • The reranker-cohere module enables reranking search results using a Cohere reranker API.
  • This module uses a third-party API and may incur costs. Make sure to check the Cohere pricing page before applying reranking to large amounts of data.
  • You will need a Cohere API key. You can request one here.
  • The default model is rerank-multilingual-v3.0
Related pages

How to enable​

Weaviate Cloud Services​

This module is enabled by default on the WCS.

Weaviate open source​

Add reranker-cohere to the ENABLE_MODULES environment variable.

Below is an example Docker Compose file, which will spin up Weaviate with the reranker-cohere module (as well as text2vec-cohere).

---
version: '3.4'
services:
  weaviate:
    command:
    - --host
    - 0.0.0.0
    - --port
    - '8080'
    - --scheme
    - http
    image: cr.weaviate.io/semitechnologies/weaviate:1.24.10
    restart: on-failure:0
    ports:
     - 8080:8080
     - 50051:50051
    environment:
      QUERY_DEFAULTS_LIMIT: 20
      AUTHENTICATION_ANONYMOUS_ACCESS_ENABLED: 'true'
      PERSISTENCE_DATA_PATH: "./data"
      DEFAULT_VECTORIZER_MODULE: text2vec-cohere
      ENABLE_MODULES: text2vec-cohere,reranker-cohere
      COHERE_APIKEY: $COHERE_APIKEY
      CLUSTER_HOSTNAME: 'node1'
...
note

Schema configuration​

The reranker-cohere module can be configured for any collection in the schema. You can also specify options such as the model to use.

This example configures the Document collection to use the reranker-cohere module, with the rerank-multilingual-v3.0 model, and to return the documents in the response.

{
  "classes": [
    {
      "class": "Document",
      ...,
      "moduleConfig": {
        "reranker-cohere": {
            "model": "rerank-multilingual-v3.0",
        },
      }
    }
  ]
}

Reranker selection​

If there is only one reranker module enabled, you don't need to do anything. The reranker module will be used by default.

Where multiple reranker modules are enabled, you must specify the reranker module to be used for each collection. You can do this by adding the desired reranker in the moduleConfig section of the schema, even without any further settings.

Set reranker for a collection
{
  "classes": [
    {
      "class": "Document",
      ...,
      "moduleConfig": {
        "reranker-cohere": {},  // This will configure the 'Document' collection to use the 'reranker-cohere' module
      }
    }
  ]
}

Model selection​

The reranker-cohere module supports the following models:

  • rerank-english-v3.0 (from Weaviate v1.24.9)
  • rerank-multilingual-v3.0 (from Weaviate v1.24.9) (default)
  • rerank-english-v2.0
  • rerank-multilingual-v2.0

You can also pass in your fine-tuned reranker model_id, such as:

  • 500df123-afr3-...

This is described further in this blog post.

Usage​

API key​

  • If the COHERE_APIKEY environment variable is not set, clients can set the API key at query time by adding this HTTP header: X-Cohere-Api-Key: YOUR-COHERE-API-KEY.

Queries​

Questions and feedback​

If you have any questions or feedback, let us know in our user forum.